Rotary furnace



Feb. 9 1926.

A. H PEHRSON ROTARY FURNACE 2 Sheet-Sheet 1 Filed June 15, 1925 Feb. 9 1926. 7 1,572,805

. A. H. PEHRSON 'ROTARY FURNACE Filed June 15. 1-925 2 SheetS-Sheet '2 Patented Feb; 9, 1926. ,7

UNITED STATES PATENT" OFFICE ADAM HELMER PEHRSON, OF BERG GRANBERGSDAL, SWEDEN/ABSIGNOR OF ONE- HALF '1O ALFRED PETTER PEHRSDN, OF KINCRAIG, ENGLAND.

, ROTARY summon.

Application filed June 15, 1925. Serial No. 8?,356.

To. all whom it may concern:

Be it known that I, ADAM HELMER Perm- SON, a subject. of the King of Sweden, residing at Berg Granbergsdal, Sweden, have invented certain new and useful Improvements in or Relating to Rotary Furnaces, of which the following is a specification.

This invention relates to rotary continuousworking furnaces of the kind that are provided with necks at the ends and with valve-like devices for distributing or controlling the supply of aeriform or gaseous fluid to openings or. tuyeres through which said fluid is supplied to the interior of the furnace. A rotary furnace having the aforesaid necks and valve-like devices has already been described in the specification of my prior British Patent No. 184810.

According to the present invention a furna-e of the above stated kind is provided with longitudinal conduits disposed at, near or in the peripheral wall thereof which conduits have lateral slots, perforations or.

a other openings through which the said aeriform or gaseous fluid enters the charge under treatment within the furnace, means being provided whereby the charge is prevented from entering said slots, perforations or openings during the rotation of the furnace. Longitudinal conduits have already been proposedfor supplying aeriform fluidto the interior of a r'otaryfurnace by valvelike distributing devices but in such cases the furnace has not been provided with an inlet ne k at one end and an outlet neck at I the. other end which is the kind of furnace to which my invention relates. For the purpose of my invention I may make the afore-' said longitudinal conduits-in the form of hollow or tubular members situated within and near the peripheral wall of the furnace and adapted to be rotated axially in such manner that during the rotation of the furnace the said slots, perforations or other openings in said members will remain downwardly directed; or the said hollow or tubular members may be adapted to remain stationary with respect to the furnace (i. e., while moving with the furnace they will not rotate axially.) in which case the said slots, perforations or other openings may be provided with lips which act as shields to pret. the ent ance of the charge there through, or a similar result may be obtained by arranging the stationary hollow or tubular members close to the peripheral wall of the furnace and byso constructing them that each comprises in cross section a short element extending inwardly from the furnace wall and having an inclined element connected thereto at the free edge and extending towards the said furnace'wall so as to leave a gap or opening close to the said furnacewallfor the aeriform or gaseous fluid to pass into thefurnace.

The aforesaid longitudinal conduits that are disposed in the furnace at or near the peripheral wall thereof are preferably so arranged that they or the outlets therefrom into the furnace are inclined to the horizontal and thus lie nearer the axis of thefurnace at the charging end than at the discharging end so that the resistance to the passage of the aeriform or gaseous fluid from said longitudinal conduits into the charge will be equalized throughout the charge which is generally deeper at the inlet end than at the outlet end.

The inlets through which the 'aeriform or gaseous fluid from the valve-likedistribub ing device enters the longitudinal conduits said longitudinal conduits or may be situmay be situated at the adjacent ends of the ated at a pointor points located some distance from the said. ends so as tothereb obtain a more even distribution of the aer1- form or gaseous fluid entering the furnace: the said inlets are preferably in the form of pipes opening into the said longitudinal conduits from either the interior or the exterior of the furnace.

The valve-like distributing device may be so construted and arranged that while operating to admit the aeriform or gaseous fluid to the longitudinal conduits covered by the charge in the furnace during one period in the rotation of the furnace, it will during another period operate to permit the gases to pass from the furnace through certain of the other longitudinal conduits that are not covered by the charge. 7

The valve-like distributing device may be in the form of a hollow stationary plug, having an arcuate opening or port therein' and said plug may be located in a correspondingly shaped rotary casing, shell or the nace and communicating with the various like having a number of openings or ports therein co-operating with said arcuate opening or port during the rotation of the furlon itudinal conduits.

'l he said furnace may be so arranged that the aeriform or gaseous fluid adm tted to one end may be of a different nature and temperature from that admitted to the other end of the said furnace.' In this case the furnace is preferably divided by a vertical partition into two com artments and the charge under treatment is transferred from the one compartment to theother during. the rotation of the furnace without allowing the gases in the one compartment to mix with the gases in the other. In some cases the furnace may be-divided into more than two compartments. For enabling the charge under treatment to be transferred from one compartment to another as afore-. said I may employ a spiral-like conduit or pipe one end of which opens into one compartment and the other end into the adjacent compartment so that as the furnace revolves the charge will be carried by the said conduit or ipefrom one compartment to another wit out however allowing the gases to pass. The aforesaid furnace when divided into two compartments asaforetaid may have valve-like distributing or controlling devices at bothends.

In order that the said invention may be clearly understood and readily carried into effect, the same will now be described more fully with reference to the accompanying gitudinal section, a transverse section on the line at w and a transverse section on the line 3 y shewing a modified arrangement of the stationary form of the aforesaid hollow or tubular members these views also shew the furnace divided into two compartments and 'provided with the aforesaid spiral-like conduit or pipe for transferring the charge from one compartment to another.

In all these figures like reference numerals indicate similar parts. 1 is the cylindrical body of the rotary furnace having in the end walls 4 and 5 thereof co-axial necks 2 and 3 through which the charge enters and leaves the furnace, the

position of the said necks being such that a Substantial body or depth of the charge dischargin are auaeos always maintained in the furnace durin its treatment; 6 and 7 are the feeding and devices with which said necks rovi ed. '16 '16 are the hollow or tubu ar members om which the aeriform or gaseous fluid enters the furnace under the control of the valve-like distributing I device with which the fluid supply chamber 9 is providedl?" a 1 Referrin first more particularly to Fignice 1 I an 2,:"the said hollow or tubular members 16 extend longitudinally alon the q furnace near the peripheral wall thereo and are so mounted in the end, walls as to be capable of. axial rotation duringthe rotation of the-furnace. for which" urpose each of them' is shewn provided with a toothed wheel '17 rin with/a central toothed wheel v18 wfii i g ch-is-so mounted as to be stationary. ,For this purpose the said toothed wheel 18 is in the example shewn bolted to a fixed standard or support 19. The hol- 'low or tubular members 16 are closed at their ends remote from the/valve-like distributing device and have lateral perforations 20 in their walls which erforations are kept downwardly directe during the rotation of the furnace owing to the axial rotation which the said members receive by the toothed wheels 17 thereon running around the fixed toothed wheel 18, all of these wheels being of the same pitch.. Entrance of the charge into said perforations is thus prevented. The aeriform or gaseous fluid 1s sugplied'through the pipe 8 to the stationary uid supply chamber 9 which in the example shewn is in the form of a conically shaped plug or member 10 co-axially arranged with. respect to the furnace. The said plug or member 10 has a ort or opening 11 of arcuate shape which proportionately corresponds in length to the length of the arouate part indicated by a b 0 (Figure 2) of the path of rotation of the furnace,

the furnace they successively come into communication with the arcuate port or open ing 11 in the plug or member 10, the dimensions of this arcuate port or opening (in the example shewn) being such that four of the said hollow or tubular members 16 are always in communication therewith and therefore supplying the acriform or fluid, to

' pipe 20 for the escape of gases coming from the furnace through the neck 2.

Referring now more particularly to Figures '3 and 4 which shew a rotary furnace like that illustrated by Figures 1 and 2 but the hollow or tubular members 16 are stationary i. e., they do not receive any axial rotation during the rotation of the furnace.

In this case the said members 16 are pro vided with lips 16 contiguous to the openings or slots 16" in the said members, said.

lips being so shaped that as the said members pass through the charge during the rotation of the furnace in the-direction of the arrow shewn in Figure 4 they act as shields to-prevent the charge from entering the openings or slots 16.

Referring now more particularly to Figures 5, 6 and 7, the said hollow or tubular members are stationary as in the last preceeding arrangement and lie closev to the inner surface of the peripheral wall of the furnace of which they form part. In this case they comprise short elements 16 extending mwardly from the furnace wall. and inclined elements 16 which at their free or inner ends lie close to the peripheral wall of the furnace so as to leave a gap or opening 17 close to the said wall for the aeriform or gaseous fluid to pass into the furnace. By

'this construction it will be seen that as the furnace revolves in the'direction of the ar-- row in Figure 6 the charge in the furnace cannot enter the said hollow members the inclined elements 16 acting more or, less as shields for the gaps or spaces 17. The aeriform or gaseous fluid is supplied'to the hollow members from the fluid supply chamber 9 by means of pipes 14 which are internally arranged within the furnace but which instead of communicating with said hollow members at the ends communicate with them at one or more lateral points as best seen in Figures 5 so as to obtain a more even distribution of the fluid entering the furnace. Obviously instead of arranging the said pipes 14 internally they may be arranged externally and communicate with the hollow members through lateral openings formed in the peripheral wall of the furnace. The stationary fluid supply chamber 9 is provided with a stationary annular flange or ring 10 having therein arcuate ports or openings 11 which may be similar to those described with reference to Figures 1 and 2; that is to say they may correspond proportionately in length with the are a b c (Figure 6). 12, 12 are 0 uings in the end wal s of the furnace w llCll communicate with the said pipes 14 and register in successive order with the arcuate ports or openings 11 in the annular flange or'ring- 10 during the rotation of the furnace, whereby those of the hollow members 16 that are covered by the charge in the furnace aresupplied with the aeriform or gaseous fluid and by them caused to penetrate the charge. In the resent example the chamber 9 is divided into two sections and the stationary annular flange or ring 10 has two arcuate terial after being treated in the one compartment is transferred to the other by the spiral-like conduit 22 which as hereinbefore stated operates to effect the transfer by revolving with the furnace without allowing the gases in one compartment to mix with those in the other. In this case a separate valve-like device is situated at each end of the furnace. The gases in compartment 101 pass off in the ordinary way through the pipe 20 (unless it is desired to remove them through the pipe 19 as aforesaid) and the gases in compartment 102 pass away through the pipe 7 The material to be treated in the first compartment 101 passes. into the latter by means of the feeding device 6-and said material is preferably treated the-rein with hot flue gases passing through the valvelike distributing device and obtained from a fire place or furnaceused for heating the;

gases which are emplovedfor treating the material in the second compartment 102. After treatment in the second compartment 102 the material may be transferred through the pipe 7 to a cooling apparatus not shewn. Said cooling apparatus may comprise a rotary chamber or drum into which are introduced cool gases which become partially heated by contact with the material in the rotary chamber or drum and maybe subduits disposed in the peripheral wall'of the furnace with lateral openings or tuyeres leading'into the interior of the furnace.

What I claim and desire to secure by Let- 'ters Patent of the United, States is 1. In a rotary furnace the combination of inlet and outlet necks at the ends, a valvelike device for controlling the supply of aeriform fluid, conduits extending lon itudin'ally ment from entering said openlngs during the rotation'of the furnace. 4 2. In a rotary furnace the combination of inlet and out-let necks at the ends, a-valvelike device for controlling the supply of aeriform fluid, conduits extending longitudinally of the furnace and disposed at the ripheral wall of the furnace and having ateral openings, means for conducting the aeriform fluid from said valve-like device to said longitudinal conduits, and means for preventing the charge in the furnace undergoing treatment from entering said openings'during the rotation of the furnace.

3. In a rotary furnace the combination of inlet and outlet necks at the ends, avalvelike device for controlling the supply of aeriform fluid, conduits extending longitudinally of thefurnace and disposed at the peripheral wall thereof and having lateral openings adapted to discharge in a direction towards the said wall, means for conducting the aeriform fluid from said valve-like device to said longitudinal conduits, and means for preventing the charge in the fur nace' undergoing treatment from entering said openings duringthe rotation of the fur-- nace. 4. In a rotary furnace the combination of inlet and outlet necks at the ends, a valvelike device for controlling the supply of aeriform fluid, conduits extending long1- tudinally of the .furnaceand each com rising a short element extending inwardly rom the furnace .wall andan inclined tubular,

element extending from said short element towards the furnace wall so as to leave a gap 'close to the furnace wall, and means for con-- ducting the aeriform fluid" fromsaid valvelike device to said conduit-s.

5. In a rotary furnace the combination of inlet and outlet necks atthe ends, a valvelike device for controlling the supply ofaeriform fluid, conduits extending longitudinally. of the furnace and eachcomprising a short element extending inwardly from the furnace wall and an inclinedelement extending'from said short element towards the furnace wall so as to leave a gap closetoj the furnace wall, andmeans for enses conducting the aeriform fluid from .said

valve-like device to said conduits at a number of lateral points,

6. In a rotary furnace the combination of. inlet and; outlet necks at the ends, a valvelike device for controlling the supply of meat from entering said openings during the rotation of the furnace.

7. In a rotary furnace the combination of inlet and outlet necks at the ends, a valve-like device for controlling the supply of aeriform fluid, conduits extending longi tudinally of the furnace and having lateral openin gipes communicating with said v'alvee evice and the said conduits at a distance from their ends, and means for preventing the charge'in the furnace undergoing treatment from entering saidopenings-during the rotation of the furnace.-

8. In a rotary furnace the combination of inlet and outlet necks at the ends, a valvelike device for controllin the admission of aeriform fluid to, the, mace and the esca e of gases therefrom, conduits extending ongitudinally of the furnace and having lateral openings, means for conducting .the aeriform fluid from said valve-like device to. those longitudinal conduits which,

are at the time covered by the charge in the furnace undergoing treatment and ses from those longitudinal conduits whic -are not covered by the charge to said valve-like device, and means for preventing the charge from entering said openings during the rotation of'the furnace.

9. ha rotar tlcal partition to divide the furnace into two. compartments, a valve-like device for controlling the supply of. aeriform fluid,

furnace and having lateral opening, means for conducting the aeriformuid 0m said valve-like device to said longitudinal con- 'duitzil means for preventing the charge in uid reventing the charge in the furnace from 1nterferwith the supplyof fluid to bothcon furnace the combination of mlet and out et necks at the ends, a verconduits extending longitudinally of the partments, and a spiral-like conduit connecting the two compartments and adapted to transfermaterial from one to the other. 11. In a rotary' furnace the combination of-inlet and outlet necks at the ends, a vertical partition to. divide the furnace into two compartments, a valve-like device at each end of the furnace for controlling the supply of aeriform fluid, conduits extending longitudinally of the furnace and having lateral openings, means for conducting the aeriform fluid from said Valve-like de vices to said longitudinal conduits, means for preventing the charge in the furnace undergoing treatment from entering said openings during the rotation of the furnace, and means for transferring the charge from one of said compartments to the other Without permitt ng the gases therein to mix.

ADAM HELMER PEI-IRSON. 

